Hemophilia A (F8) 2 Inversions
2001759
Ordering Recommendation
Identify the causal F8 gene intron 22-A or intron 1 mutation in individuals with established severe hemophilia A. The most comprehensive test for individuals with severe hemophilia A is Hemophilia A (F8) 2 Inversions with Reflex to Sequencing and Reflex to Deletion/Duplication (2001614). For mild to moderate hemophilia A, Hemophilia A (F8) Sequencing (2001747) is recommended.
Mnemonic
F8 INV
Methodology
Inverse Polymerase Chain Reaction/Electrophoresis
Performed
Varies
Reported
Within 14 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL)  
Storage/Transport Temperature
Refrigerated.  
Unacceptable Conditions
 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
Interpretive Data
Background Information for Hemophilia A (F8) 2 Inversions:
Characteristics:
Severe deficiency of factor VIII clotting activity leading to spontaneous joint or deep muscle bleeding. Moderate to mild deficiency is associated with prolonged bleeding after tooth extractions, surgery, or injuries and recurrent or delayed wound healing.
Incidence:
1 in 4,000-5,000 live male births worldwide, rare in females.
Inheritance:
X-linked recessive. Of simplex cases, 85 percent of mothers are carriers and 10-15 percent of boys have a de novo mutation.
Penetrance:
100 percent in males and 10 percent in females.
Cause:
Deleterious F8 gene mutations.
Clinical Sensitivity:
51 percent of mutations causing severe hemophilia A are detected by F8 inversion testing. This assay does not detect F8 mutations associated with mild or moderate hemophilia A in males.
Methodology:
Intron 22-A and intron 1 inversions detected by inverse PCR and electrophoresis.
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. F8 mutations, other than the F8 intron 22-A and intron 1 inversions, will not be detected.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
Note
CPT Code(s)
81403
Components
Component Test Code*Component Chart Name
2001761Hemophilia A (F8) Inversions Interp
2001762F8 Inv Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Cross References
  • DNA Analysis for Hemophilia A
  • F8
  • Carrier Detection and Prenatal Diagnosis
  • Carrier Detection of Hemophilia A
  • F8 Inversion
  • Factor VIII Deficiency
  • Factor VIII Inversion
  • Factor VIII Inversions
  • Hemophilia A
  • Hemophilia A (Factor VIII) Inversions
  • Severe Hemophilia A